President Obama's commencement address at Notre Dame yesterday is appropriately being recognized as a powerful attempt to de-escalate the nation's culture wars. Obama took advantage of an opportunity that abortion opponents had hoped to stoke into a conflagration to instead coolly call on Americans to open their hearts and minds to people who disagree with them and find common ground.

But at the same time, Obama cast that common ground in explicitly progressive terms -- and he put forth a powerful and subversive argument against the religiously-derived certainty that has played such a major role in right-wing politics in general, and the presidency of his predecessor in particular.

He embraced the controversy over abortion as the jumping-off point for a discussion of how "we must find a way to live together as one human family."

So what's the obstacle to reaching humanity's common ground? "[P]art of the problem, of course, lies in the imperfections of man -- our selfishness, our pride, our stubbornness, our acquisitiveness, our insecurities, our egos; all the cruelties large and small that those of us in the Christian tradition understand to be rooted in original sin. We too often seek advantage over others. We cling to outworn prejudice and fear those who are unfamiliar. Too many of us view life only through the lens of immediate self-interest and crass materialism; in which the world is necessarily a zero-sum game. The strong too often dominate the weak, and too many of those with wealth and with power find all manner of justification for their own privilege in the face of poverty and injustice. And so, for all our technology and scientific advances, we see here in this country and around the globe violence and want and strife that would seem sadly familiar to those in ancient times."

Former president Bush often attributed his certainty to his religious convictions, and consistently injected religiosity into the White House.

But Obama had this to say yesterday: "Remember, too, that the ultimate irony of faith is that it necessarily admits doubt. It's the belief in things not seen. It's beyond our capacity as human beings to know with certainty what God has planned for us or what He asks of us. And those of us who believe must trust that His wisdom is greater than our own.

"And this doubt should not push us away our faith. But it should humble us. It should temper our passions, cause us to be wary of too much self-righteousness. It should compel us to remain open and curious and eager to continue the spiritual and moral debate that began for so many of you within the walls of Notre Dame. And within our vast democracy, this doubt should remind us even as we cling to our faith to persuade through reason, through an appeal whenever we can to universal rather than parochial principles, and most of all through an abiding example of good works and charity and kindness and service that moves hearts and minds."

Michael D. Shear writes in The Washington Post: "The vast majority of the 12,000 in attendance at the Joyce Center basketball arena gave the president several loud, sustained ovations, and the crowd rallied to his defense when people attempted to interrupt him at the start....

"Obama did not engage in the debate over when life begins, nor did he attempt to justify his beliefs about abortion or embryonic stem cell research, positions that some said should have disqualified him from Notre Dame's honorary degree. Instead, the president took aim at the loud and angry rhetoric that he said too often dominates the discussion.

"The failure of both sides to use 'fair-minded words,' he said, overly inflames an important debate. As an example, he described his own 2004 campaign Web site, which at one point referred to 'right-wing ideologues who want to take away a woman's right to choose.'

"It was not until a doctor e-mailed him about the phrase that Obama ordered it taken down, he said.

"'I didn't change my underlying position, but I did tell my staff to change the words on my Web site,' he told the crowd. 'And I said a prayer that night that I might extend the same presumption of good faith to others that the doctor had extended to me. Because when we do that . . . that's when we discover at least the possibility of common ground.'"

E.J. Dionne writes in his Washington Post opinion column: "Obama's opponents seek to reignite the culture wars. He doesn't. They would reduce religious faith to a narrow set of issues. He refused to join them. They often see theological arguments as leading to certainty. He opted for humility....

"[I]n raising the stakes entailed in Obama's visit, the critics did the president a great service.

"By facing their arguments head-on and by demonstrating his attentiveness to Catholic concerns, Obama strengthened moderate and liberal forces inside the church itself. He also struck a forceful blow against those who would keep the nation mired in culture-war politics without end. Obama's opponents on the Catholic right placed a large bet on his Notre Dame visit. And they lost."

James Fallows blogs for the Atlantic about Obama's extraordinary ability to address complex issues -- in this case, "the difficulty of resolving, in an open democracy, differences of moral certainty that are fiercely held on all sides."

And blogger Ezra Klein, debuting on washingtonpost.com, calls attention to Obama's language shift on climate change: "'Your generation must decide how to save God's creation from a changing climate that threatens to destroy it,' Obama thundered."